Question

Burning of fuel is a ___________ (physical/chemical) change.

Answer 1

Chemical changes

• It is a permanent change and can not be reversed back.
• Change in the chemical composition of a substance takes place.
• These changes occur due to chemical reactions.
• For example- Conversion of milk to curd, rusting, burning of fuel etc

Burning of fuel

• Burning of fuel is a chemical change.
• It includes the formation of new compounds.
• Fuels are made up of hydrocarbons which on burning produce different type of gases.
• For example,

$\underset{\mathrm{Methane}\left(\mathrm{fuel}\right)}{{\mathrm{CH}}_4\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{2{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Hence, the burning of fuel is a chemical change.